Short answers, pulled from the story.
The Ju 87 was designed by Hermann Pohlmann of Junkers, who worked alongside co-designer Karl Plauth until Plauth was killed in a flying accident in November 1927. Pohlmann's guiding philosophy was that any dive-bomber had to be simple and robust, which led to the Stuka's distinctive fixed, spatted undercarriage rather than a retractable one.
The mostly complete Ju 87 V1 prototype made its maiden flight on the 17th of September 1935. It had been built by AB Flygindustri in Sweden and secretly transported to Germany in late 1934, powered by a British Rolls-Royce Kestrel V12 engine.
The Stuka's sirens were officially designated "Lärmgerät," meaning noise device in German. They were ram-air sirens mounted on the leading edges of the fixed undercarriage legs, driven by the airflow during a dive. The devices caused a speed loss of 20-25 km/h through drag, and over time were removed from many aircraft, with some bombs fitted with fin whistles as an alternative.
At exactly 04:26 Central European Time on the 1st of September 1939, a Kette of three Ju 87s from 3./StG 1, led by Oberleutnant Bruno Dilly, attacked Polish demolition charges on the rail bridges over the Vistula. This strike came 11 minutes before Germany officially declared hostilities, making it the first bombing attack of the entire war.
Approximately 6,500 Ju 87s were produced across all versions between 1936 and August 1944. The Weserflug company at Lemwerder near Bremen produced 5,930 of those, with Junkers' Dessau factory responsible for 550 of the A and B2 variants. Production finally wound down in May 1944.
The Stuka's lack of speed, manoeuvrability, and defensive armament made it highly vulnerable to fighter aircraft once it faced coordinated opposition. During the Battle of Britain in 1940-1941, it required a heavy fighter escort to operate at all. The Luftwaffe withdrew it from the campaign, though no suitable replacement existed, forcing continued production until 1944.