Best tip calculator for indie hackers

There are roughly 40-60 tip calculator apps on the market, but almost all target traditional food service (servers, bartenders, delivery drivers) with UI designed for POS systems or quick phone calculations. The indie hacker segment is underserved because their tip scenarios are fragmented: some take Stripe payments with variable fees, others use Gumroad, some do coaching calls with cash tips mixed in. The common failure is assuming all tip math is the same—it isn't. Indie hackers need calculators that integrate with their actual payment processors, handle multiple currency/fee structures, and tie into their income tracking. The real gap isn't in the math itself; it's in context. A vibecoder needs a tool that speaks their language (mentions Stripe Connect, shows take-home after processor fees, integrates with their accounting), not one optimized for a restaurant hostess. The opportunity sits at the intersection of indie monetization patterns and niche-specific UX. A new entrant should focus on: (1) tight integration with indie payment platforms (Gumroad, Paddle, Lemonsqueezy, Stripe), (2) transparent fee calculation that shows what actually hits the bank account, and (3) minimal bloat—make the core calculation so fast and frictionless that it becomes the default tool indie hackers reach for.