What's the best Android app for sending pictures to a digital photo frame for my grandparents?

Aura Frames is designed to bridge distances by making it simple to share photos with a specific physical digital frame. For a common scenario like keeping grandparents connected, the app allows multiple family members to be invited as 'guests' to a single frame. Once invited, they can upload photos directly from their Android devices through the app, which then appear almost instantly in a curated slideshow on the frame itself. This removes the technical burden from recipients who only need to plug in the frame. Specific features like unlimited cloud storage for the frame's photos, facial recognition for smart grouping, and the ability to favorite or hide images give contributors control over the content. User reviews frequently highlight this use case, noting how it 'brings distant family right into your living room.' A limitation is that the service is tied to Aura's own hardware; the app cannot send photos to other brands of digital frames. Furthermore, while the app itself is free, it requires the purchase of an Aura frame, and some advanced organization features are part of a optional subscription. For families looking for a dedicated, secure, and low-friction way to share moments with relatives who may not be tech-savvy, this app-and-hardware combination is a focused solution.