What does a real estate investor's custom app actually do?

For an active investor (5-50 doors or 1-10 commercial properties), it typically does: deal pipeline (sourcing, underwriting, offer, escrow, closed), proforma calculator (cash flow projection, IRR, cap rate, cash-on-cash return), property management (tenants, leases, maintenance), partner/LP communications (investor portal with K-1s and distributions), and document storage (contracts, leases, inspections). All linked, all searchable, all on one platform.

How does this compare to DealCheck, Stessa, or AppFolio?

DealCheck is good for one-off deal analysis but doesn't track ongoing portfolios. Stessa is good for portfolio tracking and bookkeeping but doesn't model deals being analyzed. AppFolio Investment Management is enterprise-grade and overpriced for most active investors ($400+/month per portfolio plus per-tenant fees). The custom build covers all three workflows in one app at $300/month total.

Can I model GP/LP waterfalls and equity splits?

Yes, fully. The waterfall calculation (preferred return, catchup, promote tiers) is a few hundred lines of TypeScript that you can describe in plan mode and Rork generates. Your custom app handles tiered waterfalls, preferred returns, hurdle rates, IRR-based promotes, all the standard structures.

What about tenant management and rent collection?

Built-in. Lease records, monthly rent ledger, late fees, online rent payment via Stripe or Plaid, maintenance request flow with photos. For a small landlord (5-30 doors), this replaces $50-$150/month tools like Avail, Hemlane, or TurboTenant. For larger portfolios, it complements rather than replaces dedicated property management software.

Can I share the app with my LPs / investors?

Yes. Same Rork project, role-based access via Supabase row-level security. LPs see only their deals, their distributions, their K-1s. GPs see everything. Custom branding. Push notifications when new distributions land. Patient investor relations professionalism, at SMB cost.

What about complex transactions (1031 exchanges, syndications, opportunity zones)?

1031 exchanges and opportunity zone deals are mostly date-and-document tracking, easy to model. Syndications with multi-tier LP structures, that's where the waterfall complexity kicks in. The custom app handles up to 5-tier waterfalls easily. For unusual structures (preferred equity with kickers, joint ventures with multiple GPs), build the calc once and reuse.

How long does it take to build a working real estate investment app?

v1 with deal pipeline, proforma calculator, and document storage: 30 to 45 days. Adding property management, tenant ledgers, LP portal: 45 to 75 days more. Full system with waterfalls, K-1 generation, accounting integration: 90 to 120 days. Most operators start with deal pipeline + proforma and add modules over time.

How to Build a Real Estate Investment App in 2026 (Proforma, Cash Flow, Deal Tracking)

A real estate investor running 10 doors or 5 commercial properties has a unique software problem: every tool they need exists, but no tool covers the workflow they actually run.

DealCheck and BiggerPockets analyze one-off deals well. Stessa tracks portfolio cash flow but doesn't model new deals. AppFolio Investment Management has the LP portal but charges enterprise prices and assumes you have a back office. Yardi is too heavy. Buildium and AppFolio Property Manager focus on tenants, not investors.

The right tool for an active investor with a growing portfolio doesn't exist as a SaaS. It exists as a custom build in 2026 for $300/month all-in.

This is the playbook.

What an Active Investor's Custom App Does

Deal Pipeline (the front of the workflow)

Lead sourcing: properties under consideration with source (MLS, off-market, wholesaler).
Underwriting: proforma calculator with cash flow projection, IRR, cap rate, cash-on-cash return.
Offer tracking: written, countered, accepted, lost.
Escrow: docs, inspections, financing, closing timeline.
Closed: moves to portfolio module.

Proforma Calculator

The heart of the underwriting workflow. Inputs:

Purchase price, closing costs, rehab budget.
Loan terms (interest rate, amortization, points, escrow).
Income (rent roll, vacancy assumption).
Expenses (taxes, insurance, management, maintenance, capex reserves).
Exit assumption (cap rate, sale year).

Outputs:

Year 1 to year N cash flow.
IRR (levered and unlevered).
Cash-on-cash return.
Equity multiple.
Sensitivity analysis (toggle assumptions, see results live).

This is what investors will use 100 times a year. Building it custom means the assumptions and formulas match your underwriting philosophy exactly.

Portfolio (the back of the workflow)

Property records with photos, documents (lease, deed, inspection report, insurance).
Tenant ledger with lease terms, monthly rent posting, late fee logic, online rent collection.
Maintenance request flow with photos (tenant submits via mobile app, you assign vendor).
Owner dashboard with portfolio cash flow vs proforma, occupancy, NOI by property.

LP / Investor Portal

For investors with partners or syndicate LPs:

Branded portal showing only their deals.
Distribution history with downloadable K-1s.
Quarterly investor letters.
Document vault (subscription agreements, PPMs).

Tax + Document Storage

IRS form 8825 line-item reconciliation by property.
1099-INT/MISC issuance for vendors.
1031 exchange tracking.
Document retention for the 7-year IRS rule.

The Stack

Rork for the cross-platform app (iOS + Android + web). Investor and LP-facing native mobile.
Supabase for database, auth, storage, row-level security (LPs see only their deals).
Stripe or Plaid for online rent collection.
Resend or Postmark for quarterly investor letters.
DocuSign or Dropbox Sign for subscription agreements and leases.
Twilio for SMS rent reminders to tenants.
OpenAI GPT-4o optionally for property description parsing (drop an MLS listing in, get structured data out).

Monthly cost for a 30-door portfolio with 5 LPs:

Rork: $1,800
Supabase Pro: $25
Storage: $50
E-sign: $25
Email + SMS: $50
Stripe / Plaid: per-transaction

Total: ~$1,950/month, or $23,000/year all-in.

Compare to Stessa ($25/month) + DealCheck ($50/month) + AppFolio ($400/month) + DocuSign ($45/month) + the manual work you do because they don't integrate. For an active investor, the custom build saves $5k-$30k/year plus the time you currently spend in spreadsheets.

The 90-Day Build Plan

Days 1 to 14: Deal Pipeline + Proforma

Supabase: Deal, Property, Document tables.
Deal pipeline kanban (Lead → Underwriting → Offer → Escrow → Closed).
Proforma calculator with full P&L by year, IRR, cap rate, sensitivity sliders.
Mobile app shell.

Days 15 to 45: Portfolio Module

Property records with photos and documents.
Tenant ledger with rent posting.
Online rent collection via Stripe ACH.
Maintenance request flow (tenant submits via mobile, owner assigns vendor).
Owner dashboard.

Days 46 to 75: LP Portal

Role-based access (GP vs LP).
LP dashboard with their deals only.
Distribution history.
Quarterly letter generation (template + merge fields).
K-1 upload + download flow.

Days 76 to 90: Tax + Polish

IRS form 8825 reconciliation.
1099 issuance for vendors.
Document retention rules.
Export everything to CSV for accountant.

What Real Investors Are Building

From real Rork power users (anonymized, $9,000 spender):

An aspiring real estate investor building tools across construction proformas, chat/social networking for investor circles, and legal aid support apps. 13 projects across multiple iterations.

Other real estate operators on Rork are building:

Vacation rental management with channel integration (Airbnb, VRBO API).
Commercial broker dashboards for tracking listings and showings.
Wholesale deal flow tracking for assignment-fee investors.

All running on the same Rork + Supabase stack. All saving thousands per year vs the AppFolio/Yardi enterprise quote.

The Honest Tradeoffs

What you give up vs enterprise tools (AppFolio Investment Management, Juniper Square):

No SOC 2 certification out of the box. Supabase has SOC 2; your code doesn't. For most active investors this is fine. For raising institutional capital, you may need additional compliance work.
No bank integration marketplace. AppFolio integrates with thousands of banks. Your custom build integrates with Plaid (which covers most US banks). Edge cases require manual bank syncs.
No "industry standards" reporting templates. AppFolio has 47 standard reports. Build the 3 to 5 your accountant actually uses.

For most active investors (1 to 5 syndications, 5 to 100 doors), the tradeoffs favor custom. For institutional GPs raising $100M+ funds, stick with AppFolio or Juniper Square.

What to Do This Week

If you've been building real estate underwriting in Excel and tracking deals in Notion:

Open Rork. Describe your proforma underwriting workflow.
Use plan mode to spec out the inputs, formulas, and outputs.
Build the proforma calculator first. Use it for your next deal analysis.
Add deal pipeline next, portfolio after that.

In 90 days, your underwriting plus portfolio plus LP portal all live in one app. Excel sheets stop being source of truth.