OpenStreetMap without the Map Component
Here is a way to directly access OpenStreetMaps using App Inventor2 without using the Map component. The coding is similar to how a developer would use the Google Static Map API using the WebViewer. The method is simple and uses very little code.
What you need
The app requires the following Block code, a Button, a WebViewer, a LocationSensor and a few minutes to build. The demonstration must run on a real device, not an emulator.
What the app does
The example plots a marker at your device's current location as indicated by the device GPS receiver. The location updates once a minute when you use the LocationSensor's default settings.
The method for displaying a map using the OpenStreetMap url has advantages over using the Map component. Extra features are available. The down side: the map display runs in a WebViewer which is not a fully fleshed out browser. Some OSM features work very well on an Android 7.0 but do not work on an Android 4.2.2 device.
The good stuff first. Make a long press on the map at a point interesting to you. A menu will appear.
Select what you want to do from the menu and have fun. You can plot a point and get coordinates. You may or may not be able to plot a route from your current location to that marker etc. The WebViewer is not a 'full' browser and it appears these features only work with higher Android operating systems. The web based OSM shows a distance scale in the lower left corner (eventually this feature will be available in the Map component)
The problems: all the OpenStreetMap features available using a PC and a full feature browser are not available. I can plot a route using my Android 7.0 tablet but the identical code fails in a 4.2.2 tablet (the 4.2.2 tablet 'tries' but never resolves a route). If you are lucky,long pressing a point on the map allows a menu to appear. Select Directions from here. A green marker appears. Make a second long press at a second location on the map. Select Directions to here from the menu. A red marker appears and, if you are lucky, a blue route line (route) appears too showing step by step directions to get from Green to Red..
Here is how your screen might look using Responsive Screen Sizing on a tablet:
Here is how the screen looks using Fixed Screen Sizing:
Your experience may vary, however the GPS blue marker always shows where your device thinks you are located on the map. The technique works fairly well using tablets, the smaller screens on phones might not display correctly or allow selecting options. I did not test on a small screen sized phone.
Experiment with Responsive/Fixed sizing and Classic / Device Default themes.