Offline version of room description tool

Hi there,

we would like to create an offline version of a app we currently use in an "online" version

option 1 is to "port" this in een offline version
option 2 is creating the app "from scratch" with this as a basis

(preferable android but ios is also ok)

app:
the use/goal of the app is creating room-description documents when renters
enter a property (start of the lease-contract)

the tool is currently set up that we need a constant internet connection
while going through the different "steps" (rooms and room parts)
since this is difficult (basements without phone connection etc) we need to improve
our current way of working

demo:
the current version can be found here:
http://docuweb.be/plaatsbeschrijving/

> create a property by adding a location
> then click edit
> then the user should go trough every room & every room part
>> user checks the selection boxes that are needed
>>> fex bathroom - ceiling
>>> then selects the needed info & can add extra comments / remarks
>> next room part
...
>> next room


when finished a document gets generated that is then later on copied to a different word-template.

current task is to
A create an offline version where all steps can be done without an internet connection and data
gets stored localy until the user has a connection.

B make it possible to have a "translation" table > example;
> user selects "Gipsplaten-Gyproc"
> the translation table contains
> column A: " Gipsplaten-Gyproc"
> column B: "there are Gipsplaten-Gyproc"
> value of column b gets "published" / printed in the document

current code can be found in attach
it should always be possible to add something to a room and then generate a new version of the document

please let me know
- timeline: how much time you need for this project / when will you be able to start / deliver a first version / deliver final version
- budget: please send me a budget you need to finish this project in a descent / correctly coded & well documenten way

later versions can be
- online platform where planning can already create a property and assign the task (room description of a specific location) to a user
- users can set "status" of a task (open / in progress / finished )
- ...

let me know your ideas
kind regards!
Steven