Your personal information scale for Android

Menthal is the app for digital diets, as well as a comprehensive study about mobile phone usage. The app supports a sustainable digital Lifestyle. It helps people to help themselves, by providing users with feedback regarding their phone interaction. At the samt time, the study records the mobile phone behavior of thousands of users. It thus lays the much-needed foundation for a discourse on the future of our digital society.

Proband Information

Menthal ist sowohl die App für digitale Diäten, als auch die umfassendste Studie über den Gebrauch von Mobiltelefonen. Die App unterstützt einen nachhaltigen digitalen Lebensstil. Sie leistet Hilfe zu Selbsthilfe, indem sie dem Nutzer Auskunft über seinen Umgang mit dem Telefon erteilt. Gleichzeitig erhebt die Studie das Mobilfunkverhalten tausender Nutzer. Sie legt somit die dringend notwendige Grundlage für einen Diskurs über die Zukunft unserer digitalen Gesellschaft.

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Bridging the gap between Psychology and Informatics
The study assesses the mobile phone usage behaviour of thousands of users. In particular, it measures (i) the communication behaviour and the device interaction. The former describes when and with whom the user is communicates or exchanges text messages. The phone interaction describes the frequency and duration of the phone and app use. In cooperation with the Institute for differential Psychology, the project addresses parallels between excessive phone use and non-substance addictions like gambling.
Media is covered with reports about cultural techniques and advice on healthy interaction with smartphones and online services. The scientific grounding for these tips is slim to non-existent and grossly anecdotal. Menthal constitutes the first large study which assesses these phenomena scientifically and will provide a sound empirical basis for the development of effective advice.
Proband Information


  • Montag, C., Błaszkiewicz, K., Lachmann, B., Andone, I. , Sariyska, R., Trendafilov, B., Reuter, M. & Markowetz, A. (accepted). Correlating Personality and Actual Phone Usage: Evidence from Psychoinformatics. Journal of Individual Differences.
  • Markowetz, A., Błaszkiewicz, K., Montag, C., Switala, C. & Schläpfer, T. (2014). Psycho-Informatics: Big data shaping modern psychometrics. Medical Hypotheses, 82, 405-411. [Download]
Our Team

The Menthal team consists of interdisciplinary researchers from the University of Bonn. Computer scientists and psychologists by training, they believe that the integration of both sciences will fundamentally reshape our understanding of human behavior.

Computer Science






The computer science part of the team is headed by assistant professor Alexander Markowetz. His international team is composed of Boris Trendafilov (Bulgaria), Ionut "Johnny" Andone (Romania), Mark Eibes (Germany), and Konrad Blaszkiewicz (Poland). While everybody is involved in multiple aspects of the project, each researcher has a particular focus. Boris and Ionut specialize in Android development. Mark focuses on meaningful feedback and easy to use interfaces. Konrad is responsible for data storage and analysis.

The psychological part of the team is headed by Prof. Dr. Christian Montag (Head of Molecular Psychology, University of Ulm). With Bernd Lachmann (Germany) and Rayna Sariyska (Bulgaria), he investigates how phone and Internet usage is linked to psychic processes. Besides traditional psychological questionnaires, the three frequently rely on brain scans (MRI, fMRI) and genetic markers.





Frequently asked Questions
Hey, Moment mal, wieso ist denn hier alles auf Englisch? Ich dachte, ihr seid aus Bonn.
Tatsächlich spricht nur ein kleiner Teil unseres internationalen Teams Deutsch. Im täglichen Leben verwenden wir Englisch. Daher ist die erste Version der App auch Englisch. Wir arbeiten aber fieberhaft daran, Webseite und App auf Deutsch zu übersetzen.
Which phone do I need to benefit from Menthal?
The app runs on any Android phone with version 4.0 and up.
I have forgotten my password. How can I change it?
Please go and enter your email we'll send you an email allowing you to reset it.
How long do I have to wait to obtain information on my phone usage?
Please be aware that it takes 2 to 3 days to get reliable statistics on your mobile phone use because the app starts with the first data collection after the installation.
Are there plans to support iOS (iPhone, iPad) in the future?
No, for technical reasons, we focus on the Android platform.
Which permissions does the app require?
Menthal naturally requires an extensive set of permissions which the user must provide during installation. Most notably, the app should run as an “accessibility service”. You can however, selectively disable all forms of tracking in the app's settings.
How do I enable the accessibility service?
Go to “settings”, then choose “accessibility” services, and enable “Menthal”. While this theoretically enables the app to read passwords, rest assure that it DOES NOT record any such information. Indeed, it does not record any text, audio or video. For more information, please consult our Privacy Statement.
Will Menthal eat up my data plan or battery?
No! The transferred data volume is surprisingly small, commonly comprising less than 100KB per day. Yet, to spare your data plan, we usually delay sending of the data to the server until a Wi-Fi connection becomes available.
What is data recorded for?
We store data for two purposes. First, it allows us to provide feedback on your phone usage. From your phone, we receive raw data tuples without any apparent meaning. On our servers, we analyze this data, search for patterns, or compute meaningful aggregates. For example, we will compute the number of calls you places for a particular period of time. Second, as psycho-informatic scientists, we study mobile phone usage, and how it is linked to well-being and personality. This research lays the foundation for providing saner services and interfaces for our increasingly digital age.
Do you record phone calls or videos?
No! We analyze behavior, not content. In particular we DO NOT record audio, video or written text. For example, we would record that you wrote an SMS of 103 characters at 18:37:21, but not the actual content of the message.
Is my data secure?
Yes! Your data is encrypted on your phone, and sent securely to our servers. We follow the same security standards you would find on any other sensitive webservice, such as banking or shopping.
Can I trust you with my data?
Yes! Your data will not leave the University of Bonn. We will not share the data with any third party. It will not be used for any other purpose than scientific research.
My Samsung phone starts talking. What should I do?
You need to go the settings and disable text-to-speech.
I want to delete my account. How can I do it?
Please go . After logging in you will be able to mark you account for deletion. Please take into account that full deletion of your data might up to 3 days.
Get in touch
We are happy to hear from you!