One of the biggest pet peeves that jailbreakers contend with is when the apps they depend on regularly detect that their iPhone is jailbroken and then block usage of the app as a result. One way around this is with a jailbreak bypass, but not all jailbreak bypasses are created equally, and your mileage may vary.
BawAppie open sources A-Bypass jailbreak detection bypass, empowering the community to maintain it