Default [Q] Supersnap apk extract unrooted?

Recently Google has removed a lot of Snapchat apps from the play store, including Supersnap which I use.
I am switching from my LG G2 to Xperia Z1 and would like to transfer the app, but neither phones are rooted and I can't download the app from the play store anymore despite having purchased it.

The APK is locked to ES and Astro won't back it up, can I pull it via ADB or do I need root for that?

If anyone else has the app, could they maybe back it up for me and send me the APK until I can get a hold of the dev?

Or does anyone else know of a good snapchat app that lets you send pictures from your gallery, keep and download retrieved snaps?
Current: LG Nexus 5 & LG G Pad 8.3
Retired: Garmin Nüvifone A50, HTC Desire HD, Motorola Defy, Xperia Acro S, HP Touchpad, Galaxy Nexus, Asus TF101, Galaxy S2, Galaxy S3 4G, Lumia 920, Nexus 4, Nexus 10, Surface RT, Surface Pro, Xperia Tablet Z, HTC One, LG G2, Xperia Z1