There are lot of GUI admin application for sqlite database some are free open source and some are paid. For for development on windows with Visual Studio, Sqlite.Net distribution contains Visual Studio GUI plugin for designing sqlite database.
This plug-in will be automatically loaded to your Visual Studio Installation or you can install it from Sqlite.Net installation location "SQLite.NET\bin\Designer\install.exe". This will attach SQLite.Designer.dll plugin with visual studio installation.
For using this sqlite GUI designer Open Visual Studio Server explorer from View->Server Explorer menu.
Now you can connect any existing sqlite db file or create new sqlite db file using sqlite.net provider just by right clicking on Server Explorer window->Data Connections list and selecting "Add Connection" context menu option.
In above snap you can see highlighted portions for connecting existing sqlite db or creating new sqlite db and optionally you can encrypt your data with password.
Now you are ready to work with sqlite db for designing your database tables, relations, views .....
In server explorer expand connected sqlite db and you will get three item in tree
2) System Tables
3) Views Designing sqlite tables in Visual Studio
Right click on tables in tree item you will get a context menu with option new table, by using that you can open table designer.
By right clicking on table designer window you can get several options like Set Primary Key on selected columns, insert delete column, managing relation ship between tables and can generate script for changes.
Just like this you can find several for in result set window by Query designer menu...