LastApp, Inc.
Built at OpenAI GPT-5 Startup Hackathon · Aug 9, 2025

LastApp.ai is AI based true Native Mobile App Builder. But how do we ensure Mobile Apps we built function as expected before users report? As part of Hackathon we solved this problem. We pass our screenflow initial design (Generated from user prompt originally) and ask GPT-5 API to decide each screen and what operation needs to be performed on the screen and decide on success/fail criteria. We then launch the simulator/emulator and perform the operation, then send the after screen back to GPT-5 and its own criteria from earlier and ask whether Screen functionality on app worked as expected. On success, continue to next screen and on failure, use our existing process to fix the app with help from GPT-5 API on failure reason. This is more like CUA in the API that works well with emulators/simulator. With this GPT-5 agent, after building Native Mobile Apps (Swift/iOS, Kotlin/Android, backend), we can make sure the App is fully functional and automatically fix any issues that are found.