QCAD

QCAD is an application for computer aided drafting in two dimensions (2d). It is a simple 2D CAD system for everyone. Using QCAD you can create technical drawings such as plans for buildings, interiors, mechanical parts or schemas and diagrams. QCAD works on Windows, Mac OS X and many Linux and Unix Systems. The source code of the QCAD community edition is released under the GPL (Open Source).

Spoken Tutorial Programme offered by IIT Bombay. https://script.spoken-tutorial.org/index.php/QCad


LaTeX

LaTeX is a typesetting software for document preparation, letter writing, report writing and such. When writing, the writer uses plain text and LaTeX does all the formatting, stylizing and indentation. LaTeX's prominent use is in the preparation and publication of books and articles that contain complex mathematical formulae, numbering and cross-referencing of tables and figures, chapter and section headings, the inclusion of graphics, page layout, indexing and bibliographies.

Spoken Tutorial Programme offered by IIT Bombay. https://script.spoken-tutorial.org/index.php/LaTeX
Android app using Kotlin

Android is an open source and Linux-based Operating System for mobile devices such as smartphones and tablet computers. Android Studio is the official IDE for android application development. App development on Android was almost exclusively done using the Java programming language. Kotlin is a new open-source programming language built by JetBrains, known for IntelliJ IDEA (Android Studio is based on IntelliJ IDEA). Kotlin is a language that runs on the JVM (Java Virtual Machine). Google has announced Kotlin as an official language on Android. Kotlin, is a statically typed programming language for the JVM, Android and the browser. It’s deep interoperability with Java, which attracts more Java developers. It is tools-friendly as IDE gives suggestions for Kotlin code, can convert Java code to Kotlin code. It is expressive to make your code more readable and understandable.
Spoken Tutorial Programme offered by IIT Bombay https://script.spoken-tutorial.org/index.php/Android_app_using_Kotlin