how to edit or obliterate unwanted images i.e. street lights

I don't have experience with the app, so I don't know if it has the tool, but I know photoshop has an app, and in the regular version you could work with the clone tool to 'clone' parts of the background without the lights over the lights. You may also be able to cut and paste 'clean' background over the lights and see if it blends. a soft eraser....as in an eraser where the edges are feathered or fade to opacity can also help with the blending.

Doing it is relatively easy, I've done it many times, but typing out how isn't quite as easy. And I've honestly never done it with an app. Not to say that it doesnt' exist, I just always go to a real computer for something like this

Start with the photo shop app, which I believe i free to download at least but I don't think it's totally free, and see if it has a clone tool.

Or you may need to search the app store for photo touchup apps.

Pixelmator for iOS may work for you, too, but it's not free, though.

But Pixelmator for both iOS and OS X are very good Adobe Photoshop replacement apps.

Pixelmator for iOS, basically, works nearly identical to full Adobe Photoshop.

The iOS version of Pixelmator, unlike,its OS X counterpart, the UI doesn't look anything like Photoshop's UI

Pixelmator has a cloning brush from cloning over unwanted objects in an image with a nearby desirable part of an image.

Pixelmator by Pixelmator Team

https://appsto.re/us/lUBh3.i

Good Luck to You