Hidden online Booking Database and easy synchronizable friendly Android app.

I want to know the best/fastest configuration for thid project. End users located all over South Anerica, medium to low access speed. Android version compatibilty, targeted, from 2.3 to Latest, list what you can offer. 1) Need for of a multiuser database. (DB would not need a sophisticated Web interface access as long as i can access it through Admin Android app.) Multi user accounts number starts with 200 and pro e to pass thousands access) Offer a secured access from an android app, open to suggestions. Allow superuser modif. 2) Android app is an Administrative type. Layout and using needs to be : 0 Multilanguage switchable (4 lang, we can provide translation) 1 Simple, light, FAST 2 atractive (Colourfull, fun...) Avoiding borringness. 3 use secured conex. to db 4 allow a simple calculations , ex : qties, sum. Dates 5 offer Offline consulting, editing for later sync. 6 offer deadsimple synchronizing to user. 7 Allow FAST sync of selected Tables, i.e : Data of a selected place, country or city instead of the full db content. (Tables ?) 8 Allow sending msg to Hotline and/or group captain. 9 Offer booking of qty of prposed item (no money calc needed) 10 Historial of items booked. 11 Lowest memory print, please specify your own app example 11 Lost/reset password Auto feature, secrete answer, etc.. 3) Other needs : Source code will belong to us. Javascript prefered but not compulsory Option for an Sms activation code. User Sign up, sign in, through app. (?) For superadmin user(s) Allow filtering, sorting and exporting to pdf. Allow promoting of end user to higher role, ie : VIew a group of users data. View on various groups. One by one. Accept/ignore/Blacklist user, access/subscription (email) Option for submiting small text to end users as follow: Target end users by place AND/OR language and Additional criteria. Save Targeted selections for reuse latter. Submit a List of items with required qties to return for each by end user. item ref code, descript, qty field, language/flag, item thumb image Vectorial or other. Reject/accept tick field by item lines. submit button. Confirm/cancel booking resumé. (End user Id account transmited to DB) All data sent to Online Db must be viewable by admin(s) Option to Delete, confirm and archive bookings options to sort filter and export bookings for group captain. Option to submit a similar invitation content to a selected group but with customized username in it. Options to edit a list of specific task to distinc users and send it atonce. Option to send a message with a small Map image (or link) within. Option to be advised that end user has read a mesage. User display must be resizable from a Smartphone small size to a Tablet 8 or 10 size. Any questions, feel free to contact. Any existing similar feature sampke App, let me know. Probably forgetting few features but, i need to figure so far how much that can cost. App can be delivered in just 1 of the 4 lang, as long as long we can enter translations without requiring editing the code. (In other word Not hard coded) English, Castellano,Français, Portugues