It is easy to install a dozen travel apps and use none of them well. A lean toolkit you actually open beats a crowded home screen every time. Aim for one reliable app per job rather than three competing ones.
Cover the core jobs: a flight tracker that pushes gate and delay alerts, an expense capture tool, offline maps for when data is patchy, and a secure place for your documents and passes. Add your primary airline and hotel apps for mobile check-in and quick changes. That is usually enough.
Set them up before the trip, not at the gate. Log in, enable notifications, and download offline data at home on stable wifi. An app you configure under pressure is an app that fails you when it matters.