If you are looking for more advanced apps for complex use cases as opposed to simple single table/sheet data then Axonator.com is a great choice. It allows you to collect more rich data like pictures with annotations, conditional logic, custom backend business logic, drag and drop form builder. Data can go directly into spreadsheets or any databases/APIs. Axonator is different because it allows your to model complex relationships between data tables. With its UI first approach, no knowledge of data modeling is required. It spits out native high performance IOS and Android apps without the hassle of coding. Enterprise are using this tool for quality inspections, surveys and automatically generate PDF reports and display the collected data in the form of insightful dashboards.