These are products I use in my own RV and recommend to my clients:
The links below may be affiliate links. This means that if you purchase items through these links, I might earn a small commission at no extra cost to you. Your purchases are always anonymous.
Water Pressure Regulator. Water pressure can fluctuate wildly from park to park, and even from day to day within a park. A regulator can prevent water leaks and avoid costly repairs.
3M Command Hooks. Hang anything anywhere with all kinds of Command Hooks, without damaging (most) interior surfaces.
RVLock Keyless Entry. Replace your door’s deadbolt with this keyless entry system and never forget your keys again.
Tire Pressure Monitoring System (TPMS). I’ve been using a TST 507 system with cap sensors (replaces valve stem caps, not mounted inside the tire) for temperature and pressure monitoring of RV tires while on the road.