This app was mentioned in 5 comments, with an average of 1.80 upvotes
I've tried them all (paid for two that were more than $10 each) and the best of all of them is Oruxmaps. I'm sending to to the donate version but there is a free version as well.
https://play.google.com/store/apps/details?id=com.orux.oruxmapsDonate
Android user here:
Oruxmaps software to view maps, record tracks, create or download gpx files follow routes, etc. Negatives : Akward wierd interface. Positives : Does everything. (I compare it as Gimp vs Photoshop)
I have donated in the past to help keep the project running but it seems that the website isn't working right now, the app is very much available but Google Play changed their terms and thst caused some of the versions to dissapear. It is well worth a look and I use it exclusively now on my phone as a GPS. I don't know if you have to donate now to get the app, give it a try.
Like I said, the website doesn't seem to work at the moment, I hope their project is OK because the software is ace https://www.oruxmaps.com/cs/en/more/downloads
Here is the Google play link for the app, the interfsce feels clunky at first but I think it's because they have included so many wonderful features it feels a little overwhelming coming from simpler apps. https://play.google.com/store/apps/details?id=com.orux.oruxmapsDonate
The maps themselves, I've tried so many and I like the clear lol and feel of the following. I know others who swear by talkietoastie and others but in the UK I use OS, everywhere else I use OoenAndroMaps.
OpenAndroMaps with Elevate4, the actual maps which can be downloaded by country and a pleasing theme to view the data. Both are needed to get the most out of it.
Offline mapping for everywhere I've needed with variable detail showing on different zoom levels.
All countries can be installed directly from the website once you have Oruxmaps on the phone, by https://www.openandromaps.org/downloads/laender-und-regionen
https://www.openandromaps.org/kartenlegende/elevation-hike-theme
Addons
*More accurate elevation data. * I would also look to download DEM files to get altitude readings for the region, for more accurate route planning. Here is a cached page of their blog as its offline at the moment... http://webcache.googleusercontent.com/search?q=cache:https://www.oruxmaps.com/cs/en/blog/25-dem-files&prmd=ivn&strip=1&vwsrc=0
Routing. Secondly, if you have the storage, get BRouter and grab the routing data for the region you need which means you can offline search for cycle/walk/drive routes from a to be through x y and z.
World overview map from OpenAndroMaps if you have the storage, very useful as an atlas to indicate which country data you need to get next... https://www.openandromaps.org/downloads/ubersichts-karten
In the UK I use Viewranger as I had paid for 1:25k OS maps but it seems to be more of an advertising platform for it's own trails nowadays.
Please excuse grammar etc, I'm on a phone.
Me and my mate just came back from a very small straight line mission here in the Netherlands. It's a much more densely populated area than most of the UK, so this was already quite the challenge.
Anyway, for navigating the line and recording my track I used OruxMaps on my phone (Google Play, paid: here or slightly outdated version but stable: here).
For the actual map I use Openandromaps , it has quite a high level of detail for a free map.
I planned the line using a combination of Google Earth and the feature in Google maps called 'my maps' which allows for easy adjustments of the line (much more so than Google Earth IMO).
As for analysing the elevation of your line, I suppose Google Earth could be used as well. I did notice some inaccuracies here though (yes, even in a country as flat as a flippin' pancake).
Have a look at Oruxmaps https://play.google.com/store/apps/details?id=com.orux.oruxmapsDonate