Operations veteran ships PromptSpend mobile app, shares hard lessons from store approvals to layout bugs

PromptSpend, an open-source LLM cost calculator built by a 15-year operations professional, is now live on both the Apple App Store and Google Play. The app lets users estimate AI feature costs across roughly 80 models from 12 providers by pasting a sample conversation and selecting expected traffic volumes. To ensure pricing accuracy, the app fetches a live catalog on launch rather than bundling a static file, refusing to calculate if cached data exceeds 24 hours old. All token counting is performed on-device with no user data uploaded, stored, or tied to any account or analytics identifier. The developer noted that store enrollment — including Apple's individual-to-organization conversion and Google Play's mandatory 14-day closed test with 12 testers — proved more time-consuming than the coding itself, advising others to budget weeks, not days, for that process.