If you have a level in you iPhone use it... I do, works great. The level is on the same app as your compuss. It is accurate within one degree.
... as for blocks... I'm still using wooden blocks... they are fairly light weight, and expendable.... inexpensive to replace.
Down side... getting down to fool with them is a real chore. My every joint has been adjusted, had steorid shots, PT, or surgery... just getting in and out of the trucks cab is an effort... the cabover bed is highter than it used to be.
A message to the smarty pants comment about tents.... I was doing that more than 70 years ago and quit in the 1960's... It won't be nearly as long before you won't be able to crawl in and out of a tent as you think it will... setting up a large A wall tent is a lot of work... and confines you to one place. I like to move on a moments notice.
Capt PJ.... Alaskin Cruise line ship captain, ferry captain, work boat captain has had his share of very hard work, harsh weather, and also cross country adventures in his TC(s)... he is intellegent enough to find solutions to problems... not bully someone for working on solutions.
Go for your solution PJ... and post the results... we'll all need the solutons eventually (until we have the final solution anyway)
Sleepy