Do you find the mobile app hard to use?

I am investigating consumer-orientated mobile handset and tablet user interfaces as part of a 3 year research project for a large usability organisation. The findings from this research will be compiled to help form a "usability benchmark" for consumer applications to be enforced by the European Community, and possibly the United Nations. We hope that in the future, poor usability and lack of adherence to standards will be enforced in the same way as a lack of adherence to food hygiene, the use of inaccurate weights and measures, or poor financial advice.

As part of my work in this research, I am using MyFitnessPal on Android, iPhone, iPad and Android tablet. My remit does not include the web site itself other than where it affects the apps (the web site is being audited separately as part of a different project).

If anyone has any comments about their use of the MyFitnessPal mobile apps, please contact me as I would like to supplement my audit of these with information and opinion from those who use it. Do you find the apps hard to use? If so, can you describe what is confusing or difficult? If you find the apps easy to use, I would also like to hear your opinions on why this is.

Thanks.