How to create an app primary based on a mobile website? Are there common frameworks / tools?

Hi all,

We are currently developing a mobile website to support the experience of
our event participants (they can see the program there but also log into
our system and send messages between participants etc). We would now like
to integrate this mobile website in an app, basically because people are
more used to download apps than storing weblinks on their mobile or tablet
home screen. In addition we want to send push messages duing the event.

My question is now twofold:

a) is this at all possible? I could imagine it is possible on Android but
not on IOS as Apple protects the system and does not allow to have too
much mobile content in an app.
b) which frameworks / tools / websites exist in which I can integrate my
mobile version in an app?

For all those who are questioning why this guy is not developing the apps
right away, here is the true but sad answer: we do not have a real budget
for it and web programming is the only thing I am capable of at the moment
(regarding programming of course ).

Many thanks in advance for your answers.

Best
Thorsten