An app I recently shared with the teachers at my schools is Write About This. It is a great writing app. You can use this app in whole group or small group lessons, or as an independent activity. Prompts include a picture and a written prompt. Use can use the preloaded prompts, or create your own. The app allows you to type your response to the prompt or vocally record a response.
The free version of this app provides you with 50 preloaded prompts and the ability to try the create your own feature. The paid version allows you full access to all features and costs $3.99. Your students are sure to love this app!
Watch this video for a demonstration of the features and ideas on how to use it in your classroom.