I’m not sure the history but afaik zap is no longer maintained on iOS. Maybe replaced by zap? I think zap was only a lightning wallet. No fiat onramp, etc.

Zap wallet is a remote control for a LND node, Zap saves your authentication macaroon (a fancy cookie that lnd uses) and tls certificate on the device to make LND REST API calls. It uses a format called and connect to fit certificate and macaroon data as a connection-string or qrcode

strike is a custodial lightning wallet that only has a USD balance to make and receive payments and also includes a view into Bitcoin bought and custodied to Prime Trust (requires KYC)

zap wallet was a first gen Lightning wallet, strike is a neobank that allows you to pay Lightning invoices with USD

very different apps

Zap is no longer developed