score:3
As far as I've noticed during my visit earlier this year (around January), the bike\scooter\motorcycle parking is pretty straightforward in Taipei - almost every street has large spaces for leaving your transport (between the road and the pedestrian space). Security, though, is a different question - you may find some minor trouble in finding the place to chain your bike to.
Regarding the apps - you may find Maps.me quite useful as it works in offline mode, but I'm not 100% sure it's the best solution for this specific question.