I was wondering if making apps is haram. For example, ones that can help with productivity or communication between groups.
It's not the app, it's what it's used for.
This is analogous to asking is English haram? There are things one can say in English which are haram to say, but the English language is not the problem. Likewise, an app is not a problem in itself.
Many Muslims routinely use non-Islamic apps like clocks, email apps, and document readers, along with Islamic apps for e.g. prayer times and mosque locations. Many can be found by Googling
Quran apps etc. Indeed, many scholars of Islam use Facebook and various social media, and presumably many of them use apps. But, of course, there will be apps, such as gambling apps, which would be haram to make.
In the context of an FM radio app proposal, we have the following fatwa:
In principle, it is permissible to develop radio applications for smartphones, etc. as long as it serves an educational or religious purpose and does not entail of any sin or evil. However, it is prevalent that its usage is predominately for the wrong purposes... it would be reprehensible for one to develop a FM radio app. -- Fahad Abdul Wahab, checked and approved by Mufti Ebrahim Desai, sourced from IslamQA.org (another example is from AskImam.org in the context of games)
In the context of developing an Islam "brownie point" system:
In principle, there is nothing wrong with setting up an electronic application... However, the program must be regulated by the Sharee'ah and free from innovations. -- IslamWeb.net
In the context of making a phone app to sell Islamic information:
Making these Islamic apps... aimed at spreading the religion of Allah, and teaching Qur’an and hadeeth, is a great and blessed good deed... -- Islam Q&A