Here's a list of things I've found useful or wish that I'd know about earlier for bikepacking, camping and bike touring trips.
Apps
Maps.me : My go-to phone app used both as a backup to my dedicated bike GPS and also for zooming out and getting map context. Much better than doing same on dedicated GPS. Allows you to add GPS tracks in KML format to the map. And uses the excellent open street map layers. Crucially it lets you download the maps and use offline! All for free.
Refill.org.uk : A great app which lists public places to refill your water while out on a ride, as well as friendly shops/petrol stations etc who will let you refill for free!
yr.no :Norwegian service that gives some of the best localised weather forecasts for the UK. Donwload the apps from the homepage.
Equipment
Side loading water bottle cages : Only recently found these are a thing. Great for when you are using frame bags or have limited frame room. Lets you slide the bottle sideways out of the cage rather than pulling it upwards. Work great!
Stainless steel elongated cook pot Great shape for fitting into bike packing bags. And I can fit a cup, spork, strike steel (lighter), small gas stove burner, and small gas canister inside which makes it perfect as a cook set.