As much as I love video, I confess that audio-first/audio-only people have some strong arguments why you should think about audio as much as (if not more than) video for mobile ministry.
Here are some of their arguments:
1) Oral peoples love oral messages, so adding visuals to a story sometimes detracts from their experience of a message, rather than adding to it.
2) Audio-only recordings can avoid potential cultural snafus that may arise when inappropriate choices of colors, images, etc. lead to unintended messages being communicated to an audience.
3) Audio-only recordings may not require as much technical expertise and financial investment in equipment as audio-plus-visual recordings.
4) Some phones have no media player, so the only chance of having media played over them is through a call-in service that allows people to HEAR audio messages. There are still many phones that only play audio files—not video files.
5) Audio files are much smaller than video files of the same length, so they are faster and cheaper to download over the Internet and take up less room in space-starved phones’ memory storage.
6) As much as 80% of what makes a video good is its audio!!! Get good at producing good audio and you are 80% of the way toward making good video!
Global Recording Network’s 5Fish mobile website is a source for scripture audio in thousands of languages. Their Android app is a great tool. Other Bible materials in both audio and text form can be found at the World Bibles website.
As you consider recording your own audio resources, check out these two lessons from the Media, Mobiles and Missions Curriculum: