Google adds audio calling to Duo and file sharing to Allo

Google's video calling app Duo and messaging app Allo will soon get some oft-requested features.

Google announced the changes to its communication apps, as well as some upgrades of other apps in services, at an event in São Paulo, Brazil, on Wednesday.

When Duo originally launched, it had an odd omission: You could use it for a video call, but not an audio-only call. Now, Google fixed this; the company says audio calls will work well even on slow connections and won't eat up much data. The feature is live in Brazil now, and will be rolled to the rest of the world "in the coming days."

Google Allo is also getting an important feature: file sharing. The option was a highly requested one in some markets, and now all Android users can use the app to share .pdf, .docs, .apk, .zip, and .mp3 documents.

Google also announced its photo-organizing and backup app Photos will start backing up photos in lower quality on 2G connections -- quality good enough, Google says, to look good on a smartphone. When you connect to a Wi-Fi connection, the backed up photos will be replaced by high-quality versions. Same goes for sharing: Even when your connection is poor, you'll be able to share photos in lower quality, and they'll be replaced by nicer versions when possible.

Google's announcement post has details on some Brazil-specific new features; check it out here.