  The use of spin transfer nano-oscillators (STNOs) to generate microwave
signal in nanoscale devices have aroused tremendous and continuous research
interest in recent years. Their key features are frequency tunability,
nanoscale size, broad working temperature, and easy integration with standard
silicon technology. In this feature article, we give an overview of recent
developments and breakthroughs in the materials, geometry design and properties
of STNOs. We focus in more depth on our latest advances in STNOs with
perpendicular anisotropy showing a way to improve the output power of STNO
towards the {\mu}W range. Challenges and perspectives of the STNOs that might
be productive topics for future research were also briefly discussed.
