Yes, you can block apps on iPhone. The cleanest option uses Screen Time.
Apple already provides the underlying system through Screen Time and Family Controls. The awkward part is turning those raw permissions into something you will actually use consistently. That is where a dedicated blocker helps.
- Use Screen Time if you want the system-level enforcement Apple supports.
- Use Stillpoint if you want to start a manual focus block quickly or schedule the same weak hours each week.
- Use stronger protection if your real problem is that you keep switching the block off once you feel resistance.